For a really excellent driving sim setup, you’ll need a proper seat, steering wheel, throttle/brake/shifters, speakers, and a good sized screen. As it just so happens, actual cars have all of these elements built-in, with the exception of a screen, and of course the computer or console you’ll also need to run everything.
With this revelation in mind, hacker Andrew Rossingol (AKA “TheResistorNetwork”) decided to turn a Cadillac ELR into perhaps the most realistic sim available, at least in terms of one’s physical surroundings. To accomplish this, he used the car’s OBD port (actually one of them, as this car has two) to feed driver inputs to a Linux-based computer. This computer uses the input kernel module to treat this as feedback from a joystick, allowing any game to be played, from serious race sims to something rather silly like TuxCart. One could even see it being used for other games like pong, with the wheel controlling the position of the paddle.
Screen-wise Rossingol hooked a projector up in the garage on top of the car, projecting a road image out of the vehicle just as it would appear in real life. While this doesn’t cover the entire front windshield (or rear/sides for that matter), this could certainly be upgraded with better and/or more projectors as needed. Code is available on GitHub, and a demo of how it works can be seen above.